Ventus 2cxa with FES

Dne ponedeljek, 14. april 2014 22:17:13 UTC+2 je oseba LZ design napisala:
Some photos from 1st public presentation of Ventus 2cxa with FES during Aero 2014



https://picasaweb.google.com/1154794...noredirect= 1



Regards,



Luka

I read a comments with interest. It is a matter of good airmanship to have at least some options always available where you can land a glider.
But it is true that at FES there is no additional drag of extended pylon, and so you always have performance of pure glider at least, so more time to decide.
Additionally we have very good reliability statistic with FES. So far as I am informed nobody landed on the field due to the reason, that FES did not start. Actually when you switch ON power switch, and get green LED, and "Controller ready" message on the screen, pilot can be 99% sure that motor will start. There is no engine which would be 100% reliable, but I think FES is close to that.
Before each flight pilot needs to perform a short test run, in order to be sure that all is OK. If there is any problem in the system, is then showed already.
For comparison with existing sustainers with Solo 2350 engine, which require windmiling and decompressor, is pretty difficult and also dangerous to perform a test run on the ground, as it works only at full power. So pilot do not have any idea if the system will start until he is on 200m trying to start it. And the worse thing is that pilot needs to push a stick forward to get some speed, but when you are already low, this is not action somebody would appreciate to perform...
Those pilots who are flying with FES equipped gliders, already know the difference. Regarding the range: existing battery packs are more than sufficient for what average glider pilot really needs. You can read in book of Sebastian Kawa on page 88:
"I really would happily fly a glider which has a reliable engine that starts up quickly. It would only need to run for 15 minutes or so; it wouldn't have to get me back to the airfield, just help me to return to safer place."
And FES is just this, and much more!
I suggest you to read also text in his book on page 222 and 223 about Kawa's experiance with Solo sustainer engine.

Regards,

Luka

I have a question about the history of soaring... (I'm not asking a practical serious question.)

Has anyone tried and/or had any luck with a 'slow burn single use' solid rocket in a glider? It would have the advantage of high energy density, low drag and quick start. I suppose that it might melt something important if it were were mounted on the fuselage. What about a wing mount close to the root?

I know this idea sounds crazy, but a pop-up jet sustainer strikes me as only slightly less outrageous.

On Wednesday, April 16, 2014 2:01:28 PM UTC-7, wrote:
Dne ponedeljek, 14. april 2014 22:17:13 UTC+2 je oseba LZ design napisala:

Some photos from 1st public presentation of Ventus 2cxa with FES during Aero 2014







https://picasaweb.google.com/1154794...noredirect= 1







Regards,







Luka



I read a comments with interest. It is a matter of good airmanship to have at least some options always available where you can land a glider.

But it is true that at FES there is no additional drag of extended pylon, and so you always have performance of pure glider at least, so more time to decide.

Additionally we have very good reliability statistic with FES. So far as I am informed nobody landed on the field due to the reason, that FES did not start. Actually when you switch ON power switch, and get green LED, and "Controller ready" message on the screen, pilot can be 99% sure that motor will start. There is no engine which would be 100% reliable, but I think FES is close to that.

Before each flight pilot needs to perform a short test run, in order to be sure that all is OK. If there is any problem in the system, is then showed already.

For comparison with existing sustainers with Solo 2350 engine, which require windmiling and decompressor, is pretty difficult and also dangerous to perform a test run on the ground, as it works only at full power. So pilot do not have any idea if the system will start until he is on 200m trying to start it. And the worse thing is that pilot needs to push a stick forward to get some speed, but when you are already low, this is not action somebody would appreciate to perform...

Those pilots who are flying with FES equipped gliders, already know the difference. Regarding the range: existing battery packs are more than sufficient for what average glider pilot really needs. You can read in book of Sebastian Kawa on page 88:

"I really would happily fly a glider which has a reliable engine that starts up quickly. It would only need to run for 15 minutes or so; it wouldn't have to get me back to the airfield, just help me to return to safer place."

And FES is just this, and much more!

I suggest you to read also text in his book on page 222 and 223 about Kawa's experiance with Solo sustainer engine.



Regards,



Luka

Indeed, we have that very problem in southern Arizona. Many of our emergency landing spots are less than desirable (dirt strips on the wrong side of the mountains requiring a long arduous road retrieve, or smugglers landing spots near the border where you are likely to meet with armed villains). You can land safely there (as I have done), but the retrieve will be long and not much fun.

A modest self-retrieval of 50 km or so will get us to a town with a decent airfield with the possibility of an aero retrieve or, at worst, dinner and a bed for the night! It might even get us final glide home.

Mike

At 22:31 16 April 2014, son_of_flubber wrote:
I have a question about the history of soaring... (I'm not
asking a
practic=
al serious question.)

Has anyone tried and/or had any luck with a 'slow burn
single use' solid
ro=
cket in a glider? It would have the advantage of high
energy density, low
=
drag and quick start. I suppose that it might melt
something important if
=
it were were mounted on the fuselage. What about a
wing mount close to
the=
root?

I know this idea sounds crazy, but a pop-up jet sustainer
strikes me as
onl=
y slightly less outrageous.



Germans did Me-163. I know that it had not an 'slow burn'
solid rocket, but it was liquid fuel, but still it was glider
with rocket engine


Regards
Wolf
http://youtu.be/WCej1kZInZk

Well, I've taken a lot of heat for my suggestion. That's really how it should be when someone publishes a suggestion that's outside the norms of established safety practice. Reality is that I don't have an FES glider and if I had one I'd likely treat it quite conservatively for a long time. Getting bolder with its use would only happen if my own accumulation of experience as well as the experience of others had taught me that it was safe to do so.

Consider, though, that terrain isn't black and white, landable and unlandable; Landability is a matter of degree. Certain boulder strewn terrain would probably kill you whereas a rough pasture might take out your gear at worst. A road landing option or a narrow airstrip option might work but might send you on a ground loop. So along the spectrum of 'unlandable terrain' there would almost certainly exist a range of possibilities for the late use of FES. The reasonableness of that option is related to the strength of one's expectation that the motor will start in relation to the likely consequences if it doesn't. Luka's quote from Kawa reflects that notion.

I had the first FES in the UK in 2011. It has always operated OK when operated correctly, but statistically that is not over very many flights. I did mismanage it a couple of times in the first week, due to misunderstanding a safety interlock - the manual has since been changed to help avoid that mistake.

I do not fly over totally unlandable terrain in southern England - though I have in mountainous Scotland, where I try to keep high enough always to reach landable lowlands. Large parts of England are, however, almost unlandable because of growing crops from May to July. I am happy to fly over them relying upon a mixture of experience (there are usually, though infrequent, landable options here and there), acceptable risk (a landing in crop is risky to the glider but should be risk free to pilot - been there, done it), and FES as a last resort.

It has transformed my gliding to an extent, freeing me from need for retrieve crews and avoiding landouts which were increasingly difficult because of medical issues for me.

I have also avoided relights when failing quickly to find a thermal after a winch launch - I just switch the motor on for a few minutes.

I would not like to be without it.

Just my 2p'th. Ymmv.

Chris N

On Wednesday, April 16, 2014 5:31:37 PM UTC-5, son_of_flubber wrote:
I have a question about the history of soaring... (I'm not asking a practical serious question.) Has anyone tried and/or had any luck with a 'slow burn single use' solid rocket in a glider? It would have the advantage of high energy density, low drag and quick start.

https://www.youtube.com/watch?v=vsqg28y_s3s

As for whether or not it is practical, ask the high altitude model rocket guys how much the spend on a "shot" for one of their rockets with not near enough propellant to launch a glider. Then go take a couple of tows and see which you would rather do. But it is an interesting thought.

IMHO it doesn't matter what kind of engine you have - at the
moment you reach for the start button of any motorised glider
you have to be 100% certain in your mind that it will not start
and have planned for that possibility. Then its nice when it does
start.

The actual probability of the engine not starting may vary
depending on the type and service status of the engine system
but the short term internal mental tool of 100% certainty of non-
starting should not.

(Even with the FES)

John Galloway

On 04/16/2014 11:01 PM, wrote:

Actually when you switch ON power switch, and get green LED, and
"Controller ready" message on the screen, pilot can be 99% sure that
motor will start. There is no engine which would be 100% reliable,
but I think FES is close to that. Before each flight pilot needs to
perform a short test run, in order to be sure that all is OK. If
there is any problem in the system, is then showed already.

Have you ever considered building a pylon mounted electric sustainer,
and/or battery packs that are located in the wing? As elegant as the FES
is, the reliability of the electric solution would apply equally to a
pylon configuration electric sustainer. And if there is enough battery
power to operate the motor there must be more than enough to operate the
extraction mechanism.

Obviously it will not be quite a quick to start as FES, and there is a
possibility of a failure of the pylon mechanism which would prevent the
motor from starting, but this technology has been developed for petrol
sustainers/self launchers and should be reliable by now.

The advantage to a pylon installation is:

- No mods on the nose of the glider where tow release, pitot and/or air
vent are often mounted. This would save costs and may allow for an
easier certification process, ultimately making the technology available
on a wider selection of glider models.

- No aerodynamic drag penalty when the motor is retracted.

- Propeller protected from accidental damage on the ground.

- Many modern sailplanes are designed to accommodate a sustainer. These
should have the space and the strength to accommodate a pylon mounted
electric sustainer. Certification on these gliders should be easier.

Fitting batteries in the wing may become essential as the volume FES
currently uses to accommodate batteries would be occupied by the pylon
and motor. Batteries would need to be mounted in a container that can be
inserted/removed through the root rib. The challenges for this a

- Batteries would have to be charged in place. This has safety
implications and may require more elaborate safety circuits. (I
understand FES recommend removing batteries for charging).

- Batteries would replace some or all of the water ballast capacity.
This would require modification to, or removal of, the water ballast system.

- Rigging would be heavier and rigging aids would be recommended.


The advantage of having the batteries in the wings is that it would
circumvent the "maximum weight of non-lifting components" limitation,
allowing installation in a wider selection of gliders. It may also
facilitate increased battery capacity thus increased range. The average
battery discharge on each use will be less which should result in
improved battery life.


But once you have got a pylon electric sustainer system sorted out, I
might even be able to fit one in my LS3a!


Ian

On Thursday, April 17, 2014 2:09:58 PM UTC-6, Ian wrote:
On 04/16/2014 11:01 PM, wrote:



Actually when you switch ON power switch, and get green LED, and

"Controller ready" message on the screen, pilot can be 99% sure that

motor will start. There is no engine which would be 100% reliable,

but I think FES is close to that. Before each flight pilot needs to

perform a short test run, in order to be sure that all is OK. If

there is any problem in the system, is then showed already.



Have you ever considered building a pylon mounted electric sustainer,

and/or battery packs that are located in the wing? As elegant as the FES

is, the reliability of the electric solution would apply equally to a

pylon configuration electric sustainer. And if there is enough battery

power to operate the motor there must be more than enough to operate the

extraction mechanism.



Obviously it will not be quite a quick to start as FES, and there is a

possibility of a failure of the pylon mechanism which would prevent the

motor from starting, but this technology has been developed for petrol

sustainers/self launchers and should be reliable by now.



The advantage to a pylon installation is:



- No mods on the nose of the glider where tow release, pitot and/or air

vent are often mounted. This would save costs and may allow for an

easier certification process, ultimately making the technology available

on a wider selection of glider models.



- No aerodynamic drag penalty when the motor is retracted.



- Propeller protected from accidental damage on the ground.



- Many modern sailplanes are designed to accommodate a sustainer. These

should have the space and the strength to accommodate a pylon mounted

electric sustainer. Certification on these gliders should be easier.



Fitting batteries in the wing may become essential as the volume FES

currently uses to accommodate batteries would be occupied by the pylon

and motor. Batteries would need to be mounted in a container that can be

inserted/removed through the root rib. The challenges for this a



- Batteries would have to be charged in place. This has safety

implications and may require more elaborate safety circuits. (I

understand FES recommend removing batteries for charging).



- Batteries would replace some or all of the water ballast capacity.

This would require modification to, or removal of, the water ballast system.



- Rigging would be heavier and rigging aids would be recommended.





The advantage of having the batteries in the wings is that it would

circumvent the "maximum weight of non-lifting components" limitation,

allowing installation in a wider selection of gliders. It may also

facilitate increased battery capacity thus increased range. The average

battery discharge on each use will be less which should result in

improved battery life.





But once you have got a pylon electric sustainer system sorted out, I

might even be able to fit one in my LS3a!





Ian

Ian,
Unless I am missing something here, are you really not talking about the system in the Antares 20E or something very similar?

If, as it seems from your message, you are talking about a retrofit, please be aware that there is a tremendous amount of complexity involved in an electric installation in a glider. Assuming you can work that all out, then you would have to deal with the bureaucracy of dealing with your local aviation authority such as the: FAA, EASA, etc, etc.
With tremendous effort and money, it may actually be doable, but it may be virtually impossible to be able to legally fly your electric glider. In addition, the costs of such as system may be far more than the value of one's "pure" glider....It really is a "vexing" problem!

Thx - Renny